Not seen Snatch, but people who've seen it say it's good, Lock, Stock.. was an amusing cartoonish film, well made too.
Trouble is, you know he's going to make more of the same, no doubt with his wife in them.
If you want a decent Brit gangster film not seen through the eyes of a public schoolboy pretending to be 'street' like Guy Ritchie, try these;
Sexy Beast
Gangster No.1

older ones;
The Long Good Friday
Get Carter, (the 1971 Michael Caine one, NOT the Stallone abomination)